add exif support

build.rs

@@ -0,0 +1,94 @@
+extern crate bindgen;
+extern crate cmake;
+
+use std::env;
+use std::fs::create_dir;
+use std::fs::File;
+use std::io::Read;
+use std::path::PathBuf;
+
+fn main() {
+    #[cfg(any(feature = "exif"))]
+    {
+        let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+        let utils_build_path = out_path.join("utils");
+        if !utils_build_path.exists() {
+            create_dir(&utils_build_path).unwrap();
+        }
+        cmake::Config::new("utils")
+            .define("CMAKE_INSTALL_PREFIX", out_path.to_str().unwrap())
+            .out_dir(utils_build_path)
+            .define("ENABLE_ICONV", "OFF")
+            .define("ENABLE_STANDALONE", "ON")
+            .define("ENABLE_CXX17", "ON")
+            .define("CMAKE_BUILD_TYPE", "Release")
+            .define("INSTALL_DEP_FILES", "ON")
+            .build();
+        let dep_path = out_path.join("utils_dep.txt");
+        let mut f = File::open(dep_path).unwrap();
+        let mut s = String::from("");
+        f.read_to_string(&mut s).unwrap();
+        println!("cargo:rustc-link-lib=static=exif");
+        let l: Vec<&str> = s.split(";").collect();
+        for i in l.iter() {
+            let mut p = PathBuf::from(i);
+            let p2 = p.clone();
+            let file_name = p2.file_stem().unwrap();
+            let file_name = file_name.to_str().unwrap();
+            p.pop();
+            let pa = p.to_str().unwrap();
+            if pa != "" {
+                println!("cargo:rustc-link-search={}", pa);
+            }
+            println!("cargo:rustc-link-lib={}", file_name);
+        }
+        println!("cargo:rerun-if-changed=utils/");
+    }
+    #[cfg(feature = "exif")]
+    {
+        let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+        let exif_build_path = out_path.join("exif");
+        let utils_build_path = out_path.join("utils");
+        if !exif_build_path.exists() {
+            create_dir(&exif_build_path).unwrap();
+        }
+        cmake::Config::new("exif")
+            .define("CMAKE_INSTALL_PREFIX", out_path.to_str().unwrap())
+            .out_dir(exif_build_path)
+            .define("UTILS_LIBRARY", utils_build_path.to_str().unwrap())
+            .define("CMAKE_BUILD_TYPE", "Release")
+            .build();
+        println!("cargo:rustc-link-search=native={}/lib", out_path.display());
+        let dep_path = out_path.join("exif_dep.txt");
+        let mut f = File::open(dep_path).unwrap();
+        let mut s = String::from("");
+        f.read_to_string(&mut s).unwrap();
+        println!("cargo:rustc-link-lib=static=exif");
+        let l: Vec<&str> = s.split(";").collect();
+        for i in l.iter() {
+            let mut p = PathBuf::from(i);
+            let p2 = p.clone();
+            let file_name = p2.file_stem().unwrap();
+            let file_name = file_name.to_str().unwrap();
+            p.pop();
+            println!("cargo:rustc-link-search={}", p.to_str().unwrap());
+            println!("cargo:rustc-link-lib={}", file_name);
+        }
+        println!("cargo:rerun-if-changed=exif/");
+        let bindings = bindgen::Builder::default()
+            // The input header we would like to generate
+            // bindings for.
+            .header("exif/exif.h")
+            // Tell cargo to invalidate the built crate whenever any of the
+            // included header files changed.
+            .parse_callbacks(Box::new(bindgen::CargoCallbacks))
+            // Finish the builder and generate the bindings.
+            .generate()
+            // Unwrap the Result and panic on failure.
+            .expect("Unable to generate bindings");
+
+        bindings
+            .write_to_file(out_path.join("exif.rs"))
+            .expect("Couldn't write bindings!");
+    }
+}